Method and apparatus for manufacturing filled wafer blocks

ABSTRACT

Filled wafer blocks are made by feeding preliminary blocks at a lower level to a stacking station and then feeding a wafer sheet coated on an upper side with a spread to that location, gripping them and inverting them as they are laid on the lower block to form a filled block in the production of filled wafers and the like. The filled wafer blocks can also have uncoated sheets laid onto the blocks.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national stage of PCT/AT97/00114 filed Jun. 6,1997 and based upon Austrian national application A983/96 filed Jun. 7,1996 under the International Convention.

FIELD OF THE INVENTION

The invention relates to the production of filled wafers. Filled wafersare for instance large, basically rectangular wafer blocks with a shortheight in relation to their size, which are bordered on their upper andlower sides respectively by a flat, rectangular wafer sheet and/or by arectangular wafer sheet provided with bulges, and are filled with aspread between the wafer sheets The large filled wafer blocks aredivided into small filled wafers in the form of either small rectangularwafer pieces, or small filled hollow wafers each corresponding to abulge in the wafer block.

STATE OF THE ART

In the baked goods, wafer and sweets field large basically rectangularfilled wafer blocks, with a short height in relation to their size areknown. They consist of large wafer sheets, thin in relation to theirsize, and layers of spread between the wafer sheets. These wafer blocksare bordered respectively on their upper side by an uppermost wafersheet and on their bottom side by a lowermost wafer sheet. These waferblocks are divided into small rectangular wafer pieces or into smallhollow bodies, each corresponding to a bulge.

The wafer blocks subsequently mentioned as “flat wafer blocks” eachcontain two or more flat rectangular wafer sheets and one or more layersof spread. The height of these wafer blocks corresponds to the height ofthe small filled wafer pieces to be produced therefrom. The length andwidth of these wafer blocks correspond to a multiple of the length andwidth of the small filled wafer pieces.

The wafer blocks subsequently mentioned as “wafer blocks provided withbulges” are also defined as so-called “filled hollow wafer blocks”. Inthese wafer blocks, two flat rectangular wafer sheets, at least one ofwhich has projecting bulges on its back side, are connected with eachother at their frontal sides with a spread layer. Between the two wafersheets there are hollow spaces corresponding to the bulges, which aredefined by two opposite partial areas of the wafer sheets and are atleast partially filled with the spread. Each wafer block provided withbulges contains several small, adjacent and laterally interconnectedhollow bodies. Each of these hollow bodies consists of two parts, whichcomplement each other in forming the configuration of the respectivehollow body and are formed by opposite partial areas of the wafersheets. The configuration of each of these body parts corresponds to theconfiguration of the respective partial area of the wafer sheet, whichis either flat or provided with bulges. The filled hollow wafer block isdivided between its bulges into small filled hollow wafers, each of themcomprising a single hollow body at least partially filled with thespread and has an outer shell made of baked wafer dough. The outer shapeof these small hollow bodies or of these small hollow wafers, can be forinstance spherical or a hemispherical, cylindrical, cubical,acorn-shaped, walnut-shaped, hazelnut-shaped, praline-shaped, etc.

The small filled wafer pieces and the small filled hollow bodies areproduced in industrial quantities on continuously working productionlines which are set up for the respective final product. The largerectangular wafer blocks are an intermediate product which ismanufactured in a sandwiching machine from spread and rectangular wafersheets. In the respective production line the wafer blocks are chilledfor hardening and later divided into small filled wafer pieces or intosmall filled hollow bodies.

The rectangular wafer sheets are produced in continuously operatingautomatic wafer-baking machines, whose maximal production capacitycorresponds to a multiple of the processing capacity of the knownsandwiching machines. The wafer sheets which are produced in thewafer-baking oven or the automatic wafer-baking machine, from a fluidwafer dough consisting mainly of wheat flour and water, are cooled inthe respective production line or left to cool, and then transported toa cream-spreading device and further to the sandwiching machine. Thewafer sheets have a crunchy, rough and slightly breakable consistencyand a humidity content of a maximum 1-4% by weight.

In the production of large two-layer wafer blocks having bulges on theupper and the lower side it is known to transport the wafer sheets lyingdown in a transport device to a sandwiching machine, wherein the coatedwafer sheets are folded together in pairs with their coated sides facingeach other, thereby forming two-layer wafer blocks, which are depositedon a transport device and carried away by the same. The knownsandwiching machine consists of a folding device arranged below thetransportation plane of the transport device, whose folding elementslift the two wafer sheets of a wafer block from the transport device andswing them towards each other above the transport device. After theblock formation, the folding elements are again swung apart, therebydepositing the wafer block on the transport device. The wafer block iscarried away, out of the operating range of the folding device and itsfolding elements are lowered below the transport level. When theoperation zone of the of the folding device is free again, the two wafersheets of the next wafer block are transported within the operatingrange of the folding device and stopped there. Then the folding deviceis again set into action and the next wafer block is formed. The workingrhythm of the folding device and the pauses between two successive blockformations are attuned to the intermittent supply of the wafer sheets inpairs and are influenced by the size of the respective wafer sheets andby the weight and consistency of the spread layers. In order to keepwithin limits the effect of the mass inertia forces, generated while thewafer sheets are folded together, on the wafer sheets and their spreadlayers, the speed at which the folding elements move is increasinglyreduced with the increasing size of the wafer sheets and the increasingweight of the spread layers, which necessarily leads to a longer workcycle of the folding device and to longer pauses between successiveblock formations. Therefore the production capacity which can beachieved in the processing of wafer sheets into wafer blocks with thesandwiching machine designed as a folding device decreases with theincreasing size of the wafer sheets and the increasing weight of thespread layers. Multiple-layer blocks can not be produced with asandwiching machine based on a folding device.

In the production of large, flat wafer blocks with two or several layersit is known to feed the flat wafer sheets to a sandwiching devicewherein the wafer sheets arriving one after the other on a lower levelare individually lifted to a higher level, and formed into a block onits upper side, which is carried away from the upper side of thesandwiching device and subsequently is calibrated to a predeterminedheight. This sandwiching machine lifts each coated wafer sheet from alower level and presses it from underneath with it coated upper surfaceagainst the uncoated bottom side of a wafer sheet located in the upperlevel. In the sandwiching device, each wafer sheet lies on curvedholding members, moving from the lower level to the upper level, whichare made of segments, projecting into the travel path of the wafersheets, of two wire-like helical path rotating in countersense, whoseaxes of rotation lie outside the travel path of the wafer sheets. Thecurved holding members press from underneath against the bottom side ofthe wafer sheet and support the same only linearly. In this sandwichingdevice, the diameters and the mutual distance of the wire-like helicaltracks are adjusted to the format of the wafer sheets and increase withthe increasing size of the wafer sheets. In the case of large wafersheets and heavy spread layers, this leads to increasing breaking dangerfor the coated wafer sheets during block formation.

In the wafer baking ovens wherein the wafer sheets are produced, thetrend is towards larger and larger formats of the wafer sheets andtowards constantly increasing production capacity of the wafer ovens,with shorter and shorter time periods for the discharge of the bakedwafer sheets. Only a few years ago a wafer format of 230 mm×460 mm was amaximum. Today a format of 330 mm×700 mm is almost the rule, and the endof this development is not yet in sight. This trend requires theshortening of cycles in respective production lines connected to waferbaking ovens, and to increase the processing capability of thecomponents integrated in these production lines for the coating of thewafer sheets, the processing of wafer sheets into wafer blocks, and forprocessing the wafer blocks into smaller wafer pieces or small hollowbodies.

OBJECTS OF THE INVENTION

It is an object of the invention to improve the block formation in theproduction of filled wafer blocks, particularly in the production offilled hollow wafer blocks.

It is a further object of the invention to facilitate the blockformation for large wafer sheets, which are coated with thick spreadlayers and with heavy spread masses.

SUMMARY OF THE INVENTION

In order to achieve these objects, the invention provides a method forthe production of filled wafer blocks, which are bordered on their upperside by a top wafer sheet and on their lower side by a bottom wafersheet, with spread-coated wafer sheets in between. The wafer sheet forthe bottom of the wafer block is fed as a single-layer preliminary blockat a lower level to a stacking location, and the wafer sheets for thetop of the wafer blocks are fed as upper wafer sheets to a stackinglocation at an upper level. According to the invention, at the stackinglocation for each separate wafer block a wafer sheet is taken up fromthe upper level, reversed in a guided motion and subsequently joinedwith the upper side of the single-layer preliminary block to form atwo-layer wafer block, which has an uncoated top side and an uncoatedbottom side.

For the production of multilayer filled wafer blocks the inventionproposes to feed the wafer sheets for the bottom wafer sheets of thewafer block in the form of single-layer preliminary blocks to a stackinglocation at the lower level, to feed the wafer sheets for the rest ofthe wafer sheets of the wafer block as upper wafer sheets to thestacking location at an upper level, to take up an upper wafer sheetfrom the upper level for each separate wafer block, to reverse it in aguided motion and subsequently to join it with the upper side of asingle-layer preliminary block forming a two-layer preliminary blockwith an uncoated top side and an uncoated bottom side, and for eachfurther wafer sheet layer of the wafer block to be formed, to take up afurther coated upper wafer sheet from the upper level, reverse it in aguided motion and subsequently to join it with its coated side with theuncoated upper side of the previously formed preliminary block.

The method of the invention allows for a considerable increase in theproduction capacity of the filled wafer blocks. This applies to waferblocks which are formed only from coated wafer sheets, as well as towafer blocks which are formed from coated and uncoated wafer sheets. Theblock formation which, depending on the number of wafer sheet layers ofthe finished wafer blocks, can be a single-phase or a multiple-phaseblock formation, can take place in parallel to the feeding of the wafersheets to the stacking location and in parallel to the transport of thepreliminary blocks through the lower level. The cycles for the supply ofthe wafer sheets to the stacking location can be clearly shortened andthe wafer sheet throughput at the stacking location can be clearlyincreased. The wafer sheets can be continuously fed to the stackinglocation and the finished filled wafer blocks can be continuouslycarried away from the stacking location. The wafer blocks are eachformed on their bottom wafer sheets, while these are moved further inthe lower level. The guided motion of the upper wafer sheets reachesfrom their pickup from the upper level through the reversal and up tothe point where they are joined with the upper side of the respectivepreliminary block. The guided motion of the upper wafer sheets allowsfor a clear increase in the travel speed along the path they aresupposed to travel, without any negative influence of the mass forcesthereby generated in the coated wafer sheets on their spread masses. Themass forces are determined by the configuration of this motion path, andby changing this configuration they can be intentionally controlled andinfluenced.

According to a further feature of the invention, each upper wafer sheetcan be first reversed and then lowered in a guided motion.

According to yet another feature of the invention, each upper wafersheet can be lowered in a guided motion to the lower level and reversedduring this lowering motion.

According to further feature of the invention, each reversed upper wafersheet can be synchronized with the motion of the respective preliminaryblock, before it is joined with the upper surface of the preliminaryblock.

According to a further feature of the invention, each reversed upperwafer sheet can be stopped before it is joined with the upper surface ofthe preliminary block.

According to a further feature of the invention, each upper wafer sheetcan be guided to follow the respective preliminary block and then movedsynchronously with the same, while it is joined with the upper side ofthe preliminary block.

According to further feature of the invention, the respectivepreliminary block can be guided to follow the reversed upper wafer sheetand moved synchronously with the same, while it is joined to the upperside of the preliminary block.

According to a further feature of the invention, each reversed upperwafer sheet, for the purpose of being joined with upper side of therespective preliminary block, can be set on the upper side of thepreliminary block in a guided motion and pressed with its downwardsfacing side against the upper side of the preliminary block.

According to a further feature of the invention, for the purpose ofjoining the reversed upper wafer sheet with the upper side of therespective preliminary block, it is possible to raise the preliminaryblock and to press it against the downwards facing side of the reversedupper wafer sheet.

According to a further feature of the invention, each upper wafer sheetcan be centered before it is picked up from the upper level.

According to a further feature of the invention, for each individualwafer block it is possible to register the position of its preliminaryblock in the lower level by means of a sensor monitor, and for its upperwafer sheets to be picked up from the upper level only then when itspreliminary block was registered by the sensor monitor.

The apparatus of the invention for the production of filled waferblocks, which are bordered on their upper side by a top wafer sheet andon their lower side by a bottom wafer sheet, with wafer sheets filledwith spread in between is provided with a sandwiching device which joinsthe wafer sheets to wafer blocks and has two transport devices arrangedone above the other, which supply the wafer sheets to the sandwichingdevice at a lower and an upper transport level. According to theinvention, this apparatus is characterized in that the sandwichingdevice cooperates with the lower transport device which supplies thelower wafer sheets to the sandwiching device as single-layer preliminaryblocks, supports the preliminary blocks during block formation andcarries away the finished wafer blocks from the sandwiching device. Theupper transport device supplies the remaining wafer sheets of the waferblock to the sandwiching machine as upper wafer sheets ends in front ofthe sandwiching device. The sandwiching device is designed as a transferdevice which transfers the upper wafer sheets to the preliminary blocks,and has a movable transfer head which can be moved back and forthbetween a receiving point for the upper wafer sheets located close tothe end of the upper transport device and a discharge point for theupper wafer sheets located close to the lower transport device. Thetransfer head has an end provided with a holding device for the upperwafer sheets, which in its receiving position is pointed upwards and inits discharge position is pointed downwards.

This apparatus allows for a clear increase of the production capacity offilled wafer blocks from coated wafer sheets, or from coated anduncoated wafer sheets. The single-phase or multiphase block formationcan take place in parallel with the transport of the wafer sheets. Thisapparatus makes possible a continuous operation, whereby the upper andlower transport devices continuously supply the wafer sheets to thestacking location and the lower transport device continuously carriesaway the thereon formed filled wafer blocks from the stacking location.

The transfer head moves the respectively held upper wafer sheet with aguided motion from its receiving position to its discharge position,while reversing it, and lowers it towards the respective preliminaryblock. The guided motion of the transfer head allows for a markedincrease of its speed along its given travel path, without any influenceof the mass forces thereby generated in the coated wafer sheets on thespread mass of a wafer sheet held by the transfer head. The mass forcesare determined by the configuration of the travel path and can beintentionally controlled and influenced by changing this configuration.

According to a further feature of the invention the holding device canhave an air cushion which can be brought into contact with the uncoatedunderside of the upper wafer sheets and which can be actuated withnegative pressure for seizing the upper wafer sheets and withoverpressure for delivering the upper wafer sheets.

This construction makes possible an even distribution over the entireupper wafer sheet of the holding and pressure forces exerted by theholding device on the upper wafer sheet during block forming. This isadvantageous in the case of large wafer sheets provided with a greatnumber of bulges lying close to each other. The same applies to verylarge wafer sheets coated with heavy spread layers. The air cushionintegrated in the holding device insures a large-surface support of therespective wafer sheet during its guided motion performed by means ofthe transfer head. As a result also wafer sheets coated with heavy creamlayers can be processed into wafer blocks without the danger of breakingfor the respective wafer sheet.

According to another feature of the invention, the transfer head canhave a stop projecting beyond its frontal side, which is arranged on thefrontal margin of the transfer head and which in the discharge positionof the transfer head projects from above downwards over the frontalmargin of the upper side of the respective preliminary block.

This construction facilitates the synchronization of the motion of theupper wafer sheet carried by the transfer head with the motion of thepreliminary block trailing after the transfer head.

According to a further feature of the invention, the transfer head canhave a rear stop projecting beyond its end, which is arranged at therear margin of the transfer head and which in the discharge position ofthe transfer head projects from above downwards over the rear margin ofthe upper side of the respective preliminary block.

This construction facilitates the synchronization of the motion of thepreliminary block with the motion of upper wafer sheet carried by thetransfer head lagging behind the same.

According to a further feature of the invention, underneath the lowertransport level an up and down vertically movable elevating platformassociated with the delivery position of the transfer head can beprovided. The platform has an upwardly facing support surface parallelto the lower transport level and a stop for the respective preliminaryblock perpendicular to the lower transport level.

This construction allows the joining of the wafer sheet held by thetransfer head with the respective preliminary block, independently fromthe transfer motion of the transfer head.

According to a further feature of the invention, the transfer head canbe swung between its receiving position and its discharge position abouta horizontal pivot axis arranged between the lower and the uppertransport level.

According to a further feature of the invention the transfer device canbe designed as a multiaxial handling automaton assigned to the lowertransport level, with an outrigger rotatable about a vertical axis andbendable about a horizontal axis, which has an arm rotatable about anaxis perpendicular to the bending axis, at whose free end the transferhead is mounted.

The invention also includes a process for the production of filled waferblocks which are bordered on their upper side by a top wafer sheet andon the lower side by a bottom wafer sheet, with wafer sheets filled withspread in between. In this process a preliminary block havingrespectively an uncoated upper side and an uncoated lower side of thewafer block to be formed and at least one more coated wafer sheet arefed to a stacking location at the same level. According to the inventionat the stacking location the preliminary block is lifted in a guidedmotion and is set with its uncoated underside on top of the coated upperside of the next wafer sheet supplied to the stacking location and isjoined together with the wafer sheet to form a wafer block.

For the production of multilayer filled wafer blocks the preliminaryblock is lifted at the stacking location in a guided motion and set fromabove, with its uncoated underside, on top of the coated upper side ofthe next wafer sheet fed to the stacking location, and joined with thesame to form a further preliminary block having an uncoated upper sideand uncoated underside. For each further wafer sheet layer of the waferblock to be formed, the previously formed wafer block is lifted in aguided motion and set from above, with its uncoated underside on top ofthe coated upper side of the next wafer sheet fed to the stackinglocation and joined therewith to form a wafer block.

This method allows for a marked increase of the production capacity offilled wafer blocks made of coated and uncoated wafer sheets. The blockformation, which depending on the number of wafer sheet layers of thefinished wafer blocks is either single-phased or multiphased, can takeplace in parallel with the transport of the wafer sheets to the stackinglocation, without interrupting the same. The block formation can takeplace at the stacking location parallel to the motion of the wafersheets supplied to the stacking location. The guided motion of thepreliminary blocks allows for a marked increase of their speed along thepath they are supposed to travel, without any negative influence of thegenerated mass forces on the respective preliminary block. The massforces are determined by the configuration of the motion path and can becontrolled and influenced by changing this configuration.

According to a further feature of the invention, in order to join theuncoated underside of a preliminary block with the coated upper side ofa wafer sheet, the preliminary block can be respectively set in a guidedmotion onto the upper side of the of wafer sheet, and pressed againstthis wafer sheet with its uncoated underside.

In this variant of the process the guided motion of the respectivepreliminary block is used for joining the preliminary block and thecoated wafer sheet, which during this joining remains in the supplylevel.

According to a further feature of the invention, for the purpose ofjoining the uncoated underside of a preliminary block with the coatedupper side of a wafer sheet, the respective wafer sheet can be liftedand pressed with its coated upper side against the uncoated underside ofthe preliminary block which is kept in a holding position.

In this process variant the joining of the preliminary block with thewafer sheet takes place independently from the guided motion of therespective preliminary block, which during the joining remains in itsholding position above the supply level.

According to yet another feature of the invention, the preliminary blockcan be synchronized with the motion of the wafer sheet to be connectedtherewith, before it is joined with its uncoated underside to the coatedupper side of the sheet.

According to a further feature of the invention, the preliminary blockcan be stopped before it is joined with its uncoated underside to thecoated upper side of the wafer sheet to be connected.

According to a further feature of the invention, the preliminary blockcan follow in a guided motion the wafer sheet which has to be connectedtherewith and then synchronously moved with the sheet, while it joinsthe coated upper side of the same with its uncoated underside.

According to a further feature of the invention, the respective wafersheet to be connected with the preliminary block can follow thepreliminary block and can then be moved synchronously therewith, whilethe preliminary block is joined with its uncoated underside to thecoated upper side of this wafer sheet.

According to another feature of the invention, outside the stackinglocation at first coated and uncoated wafer sheets can be joined inpairs to form two-layer wafer blocks filled with spread, which are thensupplied to the stacking location as preliminary blocks for theformation of wafer blocks.

This process variant simplifies the block formation for large wafersheets which are coated with thick spread layers and heavy spreadmasses. This process variant provides in each wafer block a separationin space and time of the first phase of its block formation from allsubsequent phase of its block formation. The production of two-layerpreliminary blocks filled with spread in the first phase of the blockformation can also take place in parallel with the transport of thewafer sheets to the stacking location.

According to a further feature of the invention, uncoated wafer sheetscan be supplied to the stacking location as preliminary blocks for theformation of wafer blocks.

In a further development the invention proposes an apparatus for theproduction of filled wafer blocks, which are bordered on their upperside by a top wafer sheet and at their lower side by a bottom wafersheet and are filled with spread between their wafer sheets. Accordingto the invention this apparatus is characterized in that a transportdevice is provided on which for each wafer block at least onepreliminary block of this wafer block having an uncoated upper side anduncoated underside, and at least one further coated wafer sheet aresupplied to the sandwiching device and the finished wafer blocks arecarried away from the sandwiching device, and that the sandwichingdevice has a work head which can be moved back and forth with respect tothe transport device between at least two operating positions, and whichon its frontal side facing the transport device has a holding devicecomprising an air cushion which can be brought into contact with therespective preliminary block, which air cushion can be actuated withnegative pressure for seizing the preliminary block and withoverpressure for releasing it.

This apparatus allows for a marked increase in the capacity to producefilled wafer blocks made of coated and uncoated wafer sheets. The blockformation, which can be either single-phased or multiphased depending onthe number of wafer sheet layers of the finished wafer block, can takeplace in parallel with the supply of wafer sheets to the stackinglocation, without interrupting the same. This apparatus makes possible acontinuous operation, whereby the block formation at the stackinglocation takes place in parallel with the motion of the wafer sheetssupplied to the stacking location.

The work head moves the respective preliminary block seized by theholding device in a guided motion, back and forth between the workpositions. Above the transport device, the work head can be movedvertically up and down in a guided motion, or can travel in aclosed-circuit path in a guided motion.

During the production of the wafer block, the work head is constantlyengaged with the uppermost wafer sheet of the wafer block via itsholding device. With its air cushion, the work head grips the uppermostwafer sheet of the wafer block evenly and transfers the holdingrespectively pressure forces to be exerted during all phases of blockformation to the respective preliminary block. The air cushion engagesat the entire upper side of the uppermost wafer sheet. This isadvantageous in the case of large wafer sheets coated with thick andheavy spread layers, respectively in the case of preliminary blocksformed from such wafer sheets.

According to a further feature of the invention, for producing two-layerfilled preliminary blocks, along the segment of the transport devicepreceding the sandwiching device there are arranged one after the otheran upper transport device for the supply of uncoated wafer sheets, astation for positioning the uncoated wafer sheets on separate coatedwafer sheets lying on the transport device, and a calibrating devicejoining the coated and uncoated wafer sheet to form two-layer filledwafer blocks.

This construction is advantageous in the case of large wafer sheetssupporting thick and heavy spread layers, from which in a phasepreceding the block formation preliminary blocks having an uncoated topside and an uncoated bottom side are produced, which then can be moreeasily seized by the work head of the sandwiching device.

According to a further feature of the invention, the work head can havea stop projecting over its frontal side, which at the frontal margin ofthe work head projects downward over the uncoated underside of thepreliminary block held by the holding device and is associated with thefrontal margin of a coated wafer sheet lying on the transport device.

This construction facilitates the synchronization of the motion of thecoated wafer sheet with the motion of the following preliminary blockcarried by the work head.

According to a further feature of the invention, the work head can havea rear stop projecting over its frontal side, which at the rear marginof the work head projects downwards over the uncoated underside of thepreliminary block held by the holding device, and is associated with therear edge of a coated wafer sheet lying on the transport device.

This construction facilitates the synchronization of the motion of thecoated wafer sheet with the motion of the trailing preliminary blockcarried by the work head.

According to a further feature of the invention, underneath thetransport level an elevating table associated with the work head, movingvertically up and down can be provided, which has an upwards facingsupport surface parallel to the transport level. and a stop arrangedperpendicularly to the transport level for a wafer sheet lying on thetransport level.

This construction allows the preliminary block held by the work head tobe joined with the respective coated wafer sheet, independently from themovement of the work head.

According to a further feature of the invention, the sandwiching devicecan be designed as a handling automaton assigned to the transportdevice, which has an outrigger bendable about a horizontal axis, atwhose free end the work head is attached.

According to another feature of the invention, the outrigger of thehandling automaton carrying the work head can be rotatable about avertical axis.

BRIEF DESCRIPTION OF THE DRAWING

The above and other objects, features, and advantages will become morereadily apparent from the following description, reference being made tothe accompanying drawing in which:

FIG. 1 is a side view of an apparatus for the production of filled waferblocks, wherein the wafer sheets are fed to a transfer device on twolevels arranged one on top of the other;

FIG. 2 is a top view of the apparatus according to FIG. 1;

FIG. 3 is an end view of the apparatus according to FIG. 1;

FIG. 4 is a schematic side view of a further embodiment of an apparatusfor the production of filled wafer blocks, wherein the wafer sheets arefed to a transfer device on two levels arranged on top of one another;

FIG. 5 is a schematic side view of the area of block formation of anapparatus for the production of filled wafer blocks, with the courses orpaths of motion during a single-phase block formation;

FIG. 6 is a schematic side view of the block formation area with afurther embodiment of the transfer device, showing the movements duringa single-phase block formation;

FIG. 7 is a schematic side view of the block formation area with afurther embodiment of the transfer device, with the motion paths duringa single-phase block formation;

FIG. 8 is a schematic side view of the block formation area for afurther embodiment of the transfer device and with an elevating tableassociated with the lower level, with the movements during asingle-phase block formation;

FIG. 9 is a schematic side view of the block formation area with afurther embodiment of the transfer device and an elevating tableassociated with the lower level, with the paths of motion during asingle-phase block formation;

FIG. 10 is a side view of an apparatus for the production of filledwafer blocks with a sandwiching device to which the wafer sheets are fedon one level;

FIG. 11 is an end view of the apparatus in FIG. 10;

FIG. 12 is a schematic side view of a further apparatus for theproduction of filled wafer blocks with a sandwiching device to which thewafer sheets are fed on one level; and

FIG. 13 is a schematic side view of an apparatus for the production offilled wafer blocks, with a section for the production of two-layerfilled preliminary blocks and a section for processing the preliminaryblocks into multilayer filled wafer blocks.

SPECIFIC DESCRIPTION

FIGS. 1 to 3 show an apparatus for the production of filled wafer blockswhich are produced in a single-phase or multiphase process from flatwafer sheets provided with bulges.

The apparatus comprises a transport device 1, consisting of severalsuccessive transport devices, which defines a lower transport level. Onthe first transport device 1 a the wafer sheets are supplied to theapparatus. The second transport device 1 b is designed as a transportswitch, which transfers a part of the wafer sheets as lower wafer sheetsto the lower transport level, to the third transport device 1 c and theremaining wafer sheets as upper wafer sheets to an upper transportdevice 2 arranged above the third transport device 1 c. The thirdtransport device 1 sends the wafer sheets in the lower transport levelto the fourth transport device 1 d, which is associated with asandwiching device and which is equipped with a sensor 3, whichregisters the wafer sheets in the lower level to be supplied to thesandwiching device.

The upper transport device 2 consists of a first segment 2 a leadingdiagonally upwards from the lower transport level and of a subsequentsegment 2 b, which leads in an upper transport level to the sandwichingdevice and ends before the sandwiching device. At the end of thetransport device 2 a sensor 4 is provided, which registers the wafersheets to be supplied to the sandwiching device on the upper level.

The sandwiching device of the apparatus is designed as a transfer device5 (FIG. 3), which has a transfer head 7 provided on its frontal sidewith a holding device 6 for the upper wafer sheets. The holding device 6comprises an air cushion connected to a compressed air duct, which canbe actuated with negative pressure for seizing and holding the upperwafer sheets, and with overpressure for the transfer and release of theupper wafer sheets.

The transfer head 7 is moved by the transfer device 5 back and forthbetween an upper receiving area, which is located close to the frontalend of the upper transport device 2, and a lower discharge area, whichextends over the fourth transport device 1 d. In the receiving area thetransfer head 7 is turned upwards with its frontal side and is in itsreceiving position 8. In the discharge area the transfer head 7 isturned downwards with its frontal side and is in its discharge position9, wherein it is moved along above the fourth transport device 1 d tothe end of the discharge area.

The transfer head 7 is mounted at the end of the outrigger 10 of thehandling automaton 11, which moves the transfer head 7 back and forth ina guided motion, on the one hand between the receiving area and thedischarge area of the transfer device 5, and on the other hand betweenits receiving position 8 and its discharge position 9. The outrigger 10is rotatable about a vertical axis 12 and has a support arm 10 a,swingable about a horizontal bending axis 13, which in turn has asegment 10 b rotatable about the longitudinal axis of the support arm 10a, which is perpendicular to the bending axis 13, the transfer head 7being mounted at the free end of this segment. A switch box (not shown)is mounted next to the handling automaton 11, which contains the controlfor the handling automaton 11 and is connected to the same via controllines.

In every single phase of block formation of a single or multiple phaseblock forming process, an upper wafer sheet is moved in a guided motionfrom the upper transport level to the lower transport level, therebyreversed and joined with the upper side of a preliminary block lying onthe lower transport level to form a filled wafer block, which has anuncoated top side and an uncoated bottom side.

The upper wafer sheet is transferred by the upper transport device 2 tothe transfer head 7, which is in its receiving position 8 in the upperreceiving area of the transfer device 5. The holding device 6 of thetransfer head 7 seizes the upper wafer sheet at its downwards facinguncoated side and holds it securely at the transfer head 7. Subsequentlythe handling automaton 11 moves the transfer head in a guided motionfrom its receiving position 8 to its discharge position 9, and at thesame time from the receiving area to the discharge area of the transferdevice 5. Thereby the upper wafer sheet held at the frontal side of thetransfer head 7 is transported from the upper transport device 2 b tothe lower fourth transport device 1 d and at the same time itspreviously upside facing side is turned downwards.

In the discharge area of the transfer device 5 the transfer head 7.which is now in its discharge position 9, is moved along by the handlingautomaton 11 above the fourth transport device 1 d, and the reversedupper wafer sheet is joined with its downwards facing side to the upperside of the respective preliminary block to form a filled wafer block.The transfer head 7 deposits the reversed upper wafer sheet from aboveonto the preliminary block lying on the fourth transport 1 d and pressesit against the upper side of the latter. This pressure can be a resultof the guided motion of the transfer head 7 itself, whereby then thenegative pressure in the air cushion of the holding device 6 can beeliminated, and the upper wafer sheet of the just formed wafer block isreleased. The pressing of the reversed upper wafer sheet can besupported by the air cushion of the transfer head 7, whereby it isactuated with compressed air and the upper wafer sheet is pushed out ofthe holding device 6. After the release of the reversed upper wafersheet by the transfer head 7, the handling automaton 11 moves thetransfer head 7 back to its receiving position 8 and into the upperreceiving area of the transfer device 5.

In the production of two-layer wafer blocks, the wafer sheet supplied inthe lower transport level is the single-layer preliminary block of thesingle-phase block formation process, and the filled two-layer waferblock is the end product of the block formation, which is carried awayby the fourth transport device 1 d. The two-layer wafer blocks consistrespectively of a wafer sheet downwardly bordering the wafer block, asecond wafer sheet bordering the wafer block upwards and a layer ofspread mass between the two wafer sheets. For the successive productionof the two-layer wafer blocks, the first wafer sheets of the waferblocks are supplied to the transfer device 5 in the lower transportlevel, and the second wafer sheets of the wafer blocks are supplied inthe upper transport level.

In the production of a multilayer wafer block in a block formationprocess with a direct succession of block formation phases, the wafersheet supplied at the beginning of the process in the lower transportlevel is the (single-layer) preliminary block of the first blockformation phase and the first preliminary block of the block formationprocess. The end product of the first block formation phase is a filledtwo-layer wafer block lying on the lower transport level, which formsthe (two-layered) preliminary block of the second block formation phaseand the second preliminary block of the process. The end product of thesecond block formation phase is a filled triple layered wafer blocklying on the lower transport level, which either represents already thefinished product of the block formation and as such is carried away bythe fourth transport device 1 d, or it represents the preliminary blockfor a further, third block formation phase and remains on the lowertransport level during this further block formation phase. The part ofthe block formation process corresponding to a single phase is repeatedin the second and in each further block formation phase, until in thelast block formation phase the wafer blocks reach the desired number ofwafer sheet layers and are carried away by the fourth transport device 1d as finished products. The fourth transport device 1 d can then bestopped until the multiple phase block formation process has ended, andthen started again when the thereby produced finished multilayer waferblocks have to be carried away.

In the second and in each further block formation phase, theabove-described courses of motion are repeated with the second,respectively next upper wafer sheet supplied in the upper transportlevel. Thereby each time to the upper side of the previously formedpreliminary block a further wafer sheet and a further spread layer areadded. This way at the end of each block formation phase a filled waferblock results, whose uncoated upper side is formed by the now upwardsfacing underside of the coated wafer sheet reversed in the blockformation phase and whose uppermost spread layer is formed by the spreadmass of this latest reversed coated wafer sheet.

For the successive production of the filled multilayer wafer blocks, therespective wafer sheets for the lowermost wafer sheets of the waferblocks are supplied as single-layer preliminary blocks to the transferdevice 5 in the lower transport level, while the wafer sheets providedfor the rest of the wafer sheets for the wafer block are supplied to thetransfer device 5 as upper wafer sheets in the upper transport level.

The filled two-layer wafer blocks are produced in a single-phase blockformation process. Each two-layer wafer block has an uncoated bottomside formed by the underside of the first wafer sheet, and an uncoatedtop side formed by the upwards facing underside of the second wafersheet, after the second wafer sheet has been reversed. The spread masslying between its two wafer sheets can originate from the first wafersheet or from the second wafer sheet or from both wafer sheets.

If a wafer sheet coated on its upper side is supplied as a first wafersheet to the transfer device 5 and as a second wafer sheet an uncoatedwafer sheet is supplied, then the spread layer of the two-layer waferblock is formed only by the spread mass of the first wafer sheet.

If an uncoated wafer sheet is supplied to the transfer device 5 as afirst wafer sheets and a wafer sheet coated on its upper side issupplied as a second wafer sheet, then the spread layer of the waferblock is formed only by the spread mass of the reversed second wafersheet.

If respectively two wafer sheets each coated on the upper side aresupplied to the transfer device 5 as first and as a second wafer sheet,then the spread layer of the two-layer wafer block is formed by thesuperposed spread masses of both wafer sheets.

If respectively flat wafer sheets are supplied as a first and as asecond wafer to the transfer device 5, then the resulting two-layerwafer block is a flat wafer block, which is flat on its underside and onits upper side.

If to the transfer device 5 a flat wafer sheet is supplied as a firstwafer sheet and a wafer sheet with bulges is supplied as a second wafersheet, then the resulting two-layer wafer block is a wafer block havingbulges only on its upper side.

If to the transfer device 5 a wafer sheet with bulges is supplied as afirst wafer sheet and a flat wafer sheet is supplied as a second wafersheet, then the resulting wafer block is a two-layer wafer blockprovided with bulges only on its underside.

If to the transfer device 5 wafer sheets with bulges are supplied as afirst and as a second wafer sheet, then the resulting two-layer waferblock is a wafer block provided with bulges on its underside and on itsupper side.

The filled triple-layer wafer blocks are produced in a two-phased blockformation process. Each triple-layer wafer block consists of a firstwafer sheet bordering the wafer block at the bottom, a second wafersheet arranged in the middle of the wafer block, a third wafer sheetbordering the wafer block on the top, as well as a lower spread layerlocated between the first and the second wafer sheet and an upper spreadlayer located between the second and the third wafer sheet.

In the production of a triple-layer wafer block, in a first blockformation phase an upper wafer sheet is picked up from the upper level,reversed and joined as a second wafer sheet of the wafer block with thefirst wafer sheet of the wafer block supplied at the lower level to forma two-layer preliminary block. In the second block formation phase acoated upper wafer sheet is taken up from the upper level, reversed andjoined as a third wafer sheet of the wafer block with the with thepreviously formed preliminary block, to produce a finished triple-layerwafer block. The latter has now an uncoated top side formed by theuncoated underside of the reversed third wafer sheet of the wafer block,and an upper spread layer formed by the spread mass of the reversedthird wafer sheet.

FIG. 4 shows an installation for the production of filled wafer blocksin a block formation process, whereby triple-layer wafer blocks areproduced from flat wafer sheets in two-phase block formation.

For the lowermost wafer sheets of the triple-layer wafer blocks uncoatedflat wafer sheets are used. These are supplied as lower wafer sheets 14by a lower feeding device 15 in a lower level of a sandwiching device.For the remaining wafer sheets of the triple-layer wafer block coatedflat wafer sheets are used. These are supplied in an upper level to thesandwiching device as upper wafer sheets 16 by an upper feeding device17. The sandwiching device is associated with a transport device 18,which in transport direction is arranged downstream of the feedingdevice 15 and on which the wafer blocks are formed and carried away.

The sandwiching device has a similar construction with the one ofembodiment examples of FIGS. 1 to 3 and comprises a transfer head 19provided at its frontal side with a holding device for the upper wafersheets 16, which is mounted on the free end of a movable outrigger of amultiaxial handling automaton. The handling automaton moves the transferhead 19 in a guided motion from an upper receiving area associated withthe upper feeding device 17 to a discharge area associated with thelower feeding device 15, thereby turning the transfer head from itsreceiving position 20 with upwardly facing frontal side to its dischargeposition 21 with downwardly facing frontal side. In the receiving area,the transfer head 19 with its upwards facing frontal side is locatedbetween the frontal end of the upper feeding device 17 and a stationaryend stop 22, following the former in transport direction. On the frontalside of the transfer head 19 a holding device is provided whichcomprises a support surface for the uncoated underside of the upperwafer sheets 16 and an air cushion associated with the support surface.

Each block formation starts with a lower wafer sheet 14, which istransmitted by the lower feeding device 15 to the transport device 18and is transported by the same to the discharge area of the sandwichingdevice. The transfer head 19 of the sandwiching device is turned intoits receiving position 20 and is located in the receiving area betweenthe frontal end of the upper feeding device 17 and the frontal end stop22. The upper feeding device 17 transports an upper wafer sheet 16 ontothe support surface of the transfer head 19 and slides it up to thestationary end stop 22. The upper wafer sheet lies with its uncoatedlower side on the support surface and is there affixed to the transferhead by suction by means of the air cushion of the transfer head 19actuated with negative pressure. Subsequently the transfer head 19 islowered by the handling automaton in a guided motion from the receivingarea to the discharge area, and thereby turned, together with the wafersheet 16 it is holding, from its receiving position 20 to its dischargeposition 21, wherein the upper wafer sheet 16 faces downwards with itscoated side.

Before the guided motion starts, the transfer head 19 turned in itsreceiving position, is located in the receiving area associated with theupper feeding device 17. The frontal margin of the transfer head 19 isarranged close to the end of the upper feeding device 17 and the rearmargin of the transfer head 19 is arranged close to the stationary endstop 22. During the guided motion of the transfer head 19, its frontalmargin is moved forwards in the transport direction of the two feedingdevices 15 and 17, and its rear margin is moved backwards against thistransport direction. At the same time the transfer head 19 with theupper wafer sheet 16 is brought close to the lower wafer sheet 14 lyingon transport device 18 and the reversed upper wafer sheet 16 is set onthe lower wafer sheet 14 and joined with the latter into a flattwo-layer wafer block.

After the two wafer sheets 14 and 16 are joined together, the negativepressure for the air cushion is turned off and the upper wafer sheet 16is released by the holding device of the transfer head 19. Thisconcludes the first block formation phase and the transfer head 19 ismoved by the handling automaton back to the receiving area and returnedto its receiving position 20.

The two-layer wafer block lying on the transport device 18 after thefirst block formation phase was concluded, forms the preliminary blockfor the subsequent second block formation phase. In this phase the nextupper wafer sheet 16 brought to the receiving area of the sandwichingdevice is seized by the transfer head 19, reversed with the coated upperside downwards and positioned in the discharge area on the uncoatedupper side of the two-layer preliminary block, being joined therewith toform a flat triple-layer wafer block.

After the conclusion of the second block formation phase, the resultingtriple-layer wafer block is carried away on the transport device 18.

The FIGS. 5 to 8 schematically show various motion courses during asingle block formation phase from the pickup of an upper wafer sheetfrom the upper level to the delivery of the reversed upper wafer sheetto the preliminary block in the lower level. The FIGS. 5 to 8schematically show lower and upper wafer sheets coated on the upper sideand provided with bulges on the lower side during a single=phase blockformation process phase for the production of so-called hollow waferblocks, each consisting of two coated wafer sheets provided with bulges.These motion courses apply also to flat coated and uncoated wafersheets, which are joined to form two-layer or multilayer wafer blocks intwo-phase or multiple-phase block formation processes. In amultiple-phase block formation process, these motion courses are subjectonly to minor changes to the extent that they have to be adjusted to theheight of the respective preliminary blocks, which increases from blockformation phase to block formation phase.

The FIGS. 5 to 8 show respectively an installation for producingtwo-layered filed wafer blocks, provided with bulges on the upper sideand the lower side, so-called hollow wafer blocks.

The installation comprises an upper feeding device 23 which transportsthe upper wafer sheets 24 in an upper level to the receiving area of atransfer device. At the frontal end of the upper feeding device 23 asensor 25 is arranged, which registers each upper wafer sheet 24 beforeit is transported in the receiving area of the transfer device.

The installation comprises further a feeding device 26 which transportsthe lower wafer sheets 27 to the lower level of the discharge area ofthe transfer device. At the frontal end of the lower feeding device 26 asensor 28 is provided, which registers each lower wafer sheet 27 beforeit is transported in the discharge area of the transfer device.

The discharge area of the transfer device is associated with a transportdevice 29 arranged downstream of the feeding device 26, on which thefinished wafer blocks are carried away.

The transfer device of the installation comprises a multiaxial (notillustrated) handling automaton, which carries a transfer head 30,provided at its frontal side with a holding device for the upper wafersheets 24. The holding device has a recess 31 open towards the frontalside of the transfer head 30, wherein an upper wafer sheets 24 isreceived and held by means of negative pressure.

The handling automaton moves the transfer head 30 in a guided motionback and forth between the receiving area 32 close to the upper feedingdevice 23 and the discharge area 33 associated with the lower transportdevice 29 of the transfer device. During this guided motion, thetransfer head 30 is turned back and forth between its receiving positionmarked with 30 a wherein it points upwards with its frontal side, andits discharge position marked with 30 b, wherein it points downwardswith its frontal side. In the receiving area 32 the frontal margin 34 ofthe transfer head turned to its receiving position 30 a is arranged inthe immediate vicinity of the frontal end of the upper transport device23, while its rear margin 35 is remotely arranged with respect to thefrontal end of the upper feeding device 23. In the discharge area 33,the rear margin 35 of the transfer head turned in its discharge position30 b is closer to the frontal end of the feeding device 26 than is itsfrontal margin 34.

In the block formation illustrated in FIG. 5, an upper wafer sheet 24 istransported by the upper transport device 23 into the receiving area 32and introduced in the upwardly open recess 31 of the transfer headturned to its receiving position 30 a. The upper wafer sheet is securelyheld by the transfer head 30 and together with this is lowered in aguided motion into the discharge area 33, thereby being reversed to facedownwards with coated frontal side. In the discharge area 33 thereversed upper wafer sheet 24 is positioned with its downwards facingcoated frontal side on the upwards facing coated frontal side of a lowerwafer sheet 27, and is joined together with the latter to form atwo-layer wafer block provided with bulges. The lower wafer block formsthe single-layer preliminary block of this block formation. While thetransfer head 30 is lowered, its frontal margin 34 is moved forward inthe transport direction of the lower transport device 29, while at thesame time its rear margin 35 is moved backwards, oppositely to thistransport direction. During the guided motion, the transfer head 30together with the upper wafer sheet 24 held by it, is adjusted to theposition assumed on the lower transport device 29 by the preliminaryblock formed by the lower wafer sheet 27.

In the block formation shown in FIG. 6, the transfer head lowered in thedischarge area 33 and turned in its discharge position 30 b trails afterthe preliminary block 27 lying on the lower transport device 29. At therear margin 35 of the transfer head 30, a rear stop 36 projects over thecoated side of the upper wafer sheet 24 held by the transfer head 30.The transfer head 30 is brought with its rear stop 36 from behind to therear edge of the preliminary block 27 and then pushes the preliminaryblock 27 further on the lower transport device 29 in its transportdirection, until the transfer head 30 has set the upper wafer sheet 24on the top side of the preliminary block 27.

In the block formation shown in FIG. 7, the transfer head lowered intothe discharge area 33 and turned to its position 30 b is trailed by thepreliminary block 27 lying on the lower transport device 29. Thetransfer head 30 has at is frontal margin 34 a frontal stop 37 whichprojects over the coated side of the coated wafer sheet 24 held by thetransfer head 30. The preliminary block 27 on the transport device 29trails behind the transfer head 30 until the frontal margin of thepreliminary block 27 pushes against the frontal stop 37 of the transferhead 30. Subsequently the preliminary block 27 is held back by thefrontal stop 37 of the transfer head 30, until the transfer head 30 haspositioned the upper wafer sheet 24 on the upper side of the preliminaryblock 27.

In the block formation shown in FIG. 8, the preliminary block 27 lyingon the lower transport device 29 is lifted from the transport device 29by an elevating table 38 arranged in the discharge area 33 of thetransfer device and is pressed with its upper side from below againstthe downwards facing side of the reversed upper wafer sheet 24, which isheld by the transfer head lowered in the discharge area 33 and turned toits discharge position 30 b.

The lower transport device 29 has two or more endless transport belts 29a, arranged next to each other transversely to the transport direction,whose upper faces 29 b support the preliminary block 27. The verticallyup and down movable elevating table 38 has an upper support surface 39,whose size corresponds to the side of the wafer sheets, and a frontalstop 40 projecting upwards over the support surface 39 for thepreliminary blocks 27. The support surface 39 is arranged parallelly tothe transport plane of the lower transport device 28 and the stop 40 isperpendicular thereto. In the elevating table 38 longitudinal groovesparallel to the transport direction are provided, which during thelifting of the elevating table 38 receive the upper faces 29 b of thetransport belts 29 a free of contact.

The elevating table 38 can be moved back and forth between a lowerrelease position, a middle locking position and an upperpressure-exerting position. In the release position the elevating table38 with its stop 40 is lowered under the upper faces 29 b of thetransport belts 29 a. In the locking position the elevating table 38projects with its stop 40 over the upper faces 29 b of the transportbelts 29 a, while its upper support surface 39 is still located underthe upper faces 29 b of the transport belts 29 a. In thepressure-exerting position the elevating table 38 projects with its stop40 and its support surface 39 over the upper faces 29 b of the transportbelts 29 a. In the pressure-exerting position the elevating table 38presses a preliminary block 27, lying on its support surface 39 andsupported by it over its entire underside, against a reversed upperwafer sheet 24, which is held by the transfer head arranged in thedischarge area 33 and turned to its discharge position 30 b.

FIG. 9 shows an installation similar to FIGS. 5 to 8 in a blockformation similar to FIG. 8 with another embodiment of the transferdevice. In this transfer device the transfer head 30 provided with aholding device for the upper wafer sheets 24 can be swung about astationary horizontal pivot axis 41 from the receiving area 32 into thedischarge area 33 of the transfer device. The pivot axis 41 is arrangedbetween the transport level formed by the upper transport device 23 andthe transport level formed by the lower transport device 26. Like in theembodiment example of FIG. 8, in the discharge area 33 of the transferdevice a vertically up and down movable elevating table 42 is provided.In the block formation illustrated in FIG. 9, the preliminary block 27lying on the transport device 29 is lifted from the lower transportdevice 29 by the elevating table 42 and pressed from below, with itsupper side against the downwards facing side of the reversed upper wafersheet 24, which is held by the transfer head 30 swung into the dischargearea 33 and at the same time into its discharge position. Theconstruction of the lower transport device 29 and of the elevating table42 correspond to the constructions described in connection with FIG. 8.

During its travel from the upper receiving area 32 to the lowerdischarge area 33, the transfer head 30 is also swung about the pivotaxis 41 from its receiving position 30 a into its discharge position 30b. Thereby the transfer head 30 moves the upper wafer sheet 24 held bythe same first in the transport direction of the lower transport device29 over the upper transport level upwards and outwards, and then againstthis transport direction into the lower discharge area 33. In thedischarge area 33, the transfer head which is in its discharge position30 b securely holds the reversed upper wafer sheet 24 and supports itupwards, while the elevating table 42 presses from underneath thepreliminary block 27 with its upper side against the downwards facingside of the upper wafer sheet 24 and joins it therewith to form atwo-layer wafer block. Subsequently the transfer head 30 releases theupper wafer sheet 24. The two-layer wafer block is deposited on thelower transport device 29 by the elevating table 42, while the elevatingtable 42 is lowered in its release position. Now the finished waferblock can be carried away by the lower transport device 29. Before orwhile the next preliminary block is being transported on the lowertransport device 29 towards the elevating table 42, the elevating table42 itself is again lifted up to its locked position.

The FIGS. 10 and 11 show an installation for the production of filledwafer blocks with a transport device 44 defining a lower transportlevel, associated with a sandwiching device 43. For the production ofsingle-layer, two-layer or multilayer wafer blocks, the sandwichingdevice 43 is supplied by the transport device 44 with a preliminaryblock and one or more coated wafer sheets in succession. The preliminaryblock has an uncoated upper side and an uncoated underside and canconsist of a single uncoated wafer sheet, or of two-layer or multilayerwafer blocks. On the transport device 44 a sensor 45 is arranged, whichregisters preliminary blocks and wafer sheets to be supplied to thesandwiching device 43 in the lower transport level.

The sandwiching device 43 comprises a work head 46 with a frontal sidefacing the transport device 44, on which a holding device 47 with aircushion is provided. For the purpose of seizing a preliminary block theair cushion is actuated with negative pressure, and for discharging thefinished wafer block it is actuated with overpressure. The sandwichingdevice 43 moves the work head 46 back and forth between particular workpositions, which are at different distances from the transport device44.

The work head 46 is mounted to the free end of an outrigger 48 of amultiaxial handling automaton 49, which moves the work head 46 in aguided motion between back and forth between its work positions. Theoutrigger 48 is rotatable about a vertical axis 50 and has a support arm52 swingable about a horizontal bending axis 51, this arm carrying thework head 46 at its free end. Next to the handling automaton a switchbox (not shown) is arranged which comprises the control for the handlingautomaton and which is connected therewith via control lines.

For the production of filled two-layer wafer blocks, each being producedfrom a first uncoated wafer sheet and a second coated wafer sheet, asingle-phase block formation with two work positions of the work head 46is provided.

During a block formation the work head 46 is moved into a lower workposition, wherein it seizes the first uncoated wafer sheet supplied bythe transport device 44 as a preliminary block at its uncoated upperside and holds it securely with its holding device. Subsequently thework head 46 with the preliminary block is moved into the second upperwork position and joined with the second coated wafer sheet supplied bythe transport device 44 to form a two-layer wafer block, which iscarried away by the transport device 44. For the next block formation,the work head 46 is again lowered to its first lower work position.

For the production of filled triple-layer wafer blocks, each producedfrom a first uncoated wafer sheet and a second and a third wafer sheet,both of which are coated, a two-phase block formation with threepositions of the work head 46 is provided.

During a block formation in the first block formation phase, the workhead 46 is moved in its first lower work position, wherein it seizes thefirst uncoated wafer sheet supplied as a single-layer preliminary blockat its uncoated upper side and holds it securely with its holding device47. Subsequently the work head 46 is moved with the preliminary blockinto the second middle work position, wherein the single-layerpreliminary block held by the work head 46 is joined with the secondcoated wafer sheet supplied by the transport device 44 to form atwo-layer preliminary block. In the second block formation phase, thework head 46 is moved with the two-layer preliminary block into thethird upper work position, wherein the two-layer preliminary block heldby the work head 46 is joined with the third coated wafer sheet suppliedby the transport device 44 to form a triple-layer wafer block, which iscarried away on the transport device 44. For the next two-phase blockformation, the work head 46 is again moved to its lower work position.

With each block formation phase, the preliminary block held by the workhead 46 increases at its underside by one more wafer layer and one morespread layer. During the block formation the work head 46 is constantlyin engagement with the uncoated upper side of the preliminary block itis holding.

For the production of filled, three-layer wafer blocks, each producedfrom a two-layer preliminary block and a coated wafer sheet, asingle-phase block formation with two positions of the work head isprovided.

During one block formation the work head 46 is moved into its lower workposition, wherein it seizes the two-layer preliminary block supplied bythe transport device 44 at its uncoated upper side, and holds itsecurely with its holding device 47. Subsequently the work head 46 withthe two-layer preliminary block is moved into its second upper workposition, wherein it is joined with the coated wafer sheet supplied bythe transport device 44 to form a triple-layer wafer block, which iscarried away on the transport device 44.

If further wafer sheet layers, respectively spread layers, have to beadded to the triple-layer wafer blocks, then for each further wafersheet layer, respectively each further spread layer, a further blockformation phase is required, wherein in a further work position of thework head 46 on the underside of the preliminary block held by the workhead 46 a further coated wafer sheet supplied by the transport device 44is added. During a block formation, the height of the preliminary blockheld by the work head 46 increases from one block formation phase to thenext. The distance of the uncoated underside of the preliminary blockfrom the transport device 44 can remain the same during all blockformation phases.

According to the invention, the joining of a preliminary block held bythe work head 46 with a coated wafer sheet supplied by the transportdevice 44 can be done in various ways.

The joining can be performed by the handling automaton 49 through theguided motion of the work head 46. Thereby the preliminary block held bythe work head 46 can be positioned from above with its uncoatedunderside on the coated upper side of the wafer sheet lying on thetransport device 44, and can be pressed from above against the same,without releasing the preliminary block. Only in the respective lastblock formation phase the finished wafer block is released by theholding device 47 of the work head 46 in the last position of the workhead 46.

The joining can also be performed by an elevating table, which lifts thecoated wafer sheet lying on the transport device 44 and presses it frombelow against the uncoated underside of the preliminary block held bythe work head 46 in the respective work position. The construction ofthe transport device 44 and of the elevating table associated therewith,correspond to the embodiments of the lower transport device 29 and theelevating table 38 described in connection with FIG. 8.

The joining takes place within the motion path of the work head 46,which can be directed in a work area associated with the transportdevice 44 to the position assumed by the coated wafer sheet on thetransport device 44, as well as to the already existing height of thepreliminary block held the work head. After the preliminary block andthe wafer sheet have been joined, the work head 46 with the wafer blockit holds is moved out of the work area. The work area corresponds to thepath travelled by the work head 46 above the transport device 44, whichreaches from the approach point of the preliminary block held by thework head 46 towards the respective wafer sheet to the departing motionof the work head 46 with the preliminary block increased by one wafersheet layer.

In a single-phase block formation, the joining of preliminary block andwafer sheet takes place in all successive block formations within asingle stationary work area.

In a two-phase or multiple phase block formation, the joining of thepreliminary block and the wafer sheet can take place in all blockformation phases of a block formation and in all block formation phasesof successive block formations, within one stationary work area which isthe same for all block formation phases, when the transport device 44 isstopped in each case for the duration of a block formation phase.

If the transport device 44 continues to run during the block formation,then the motion of the work head 46 together with the preliminary blockit is holding is synchronized with the motion of the respective wafersheet, before the preliminary block and the wafer sheet are joined. Thiscan take place in all block formation phases in a stationary work area,whose longitudinal extent in the transport direction of the wafer sheetsis bigger than in the case of the respectively stopped transport device44. However this can also take place in different work areas, each workarea being assigned to one block formation phase.

The motion of the respective preliminary block held by the work head 46of the sandwiching device 43 can also be synchronized with the wafersheet lying on the transport device 44, as shown in the block formationof FIG. 5, by moving the work head 46 synchronously with the wafer sheetlying on the transport device 44, until the preliminary block held bythe work head 46 is positioned on top of the wafer sheet. The motion ofthe respective preliminary block held by the work head 46 can besynchronized with the wafer sheet lying on the transport device 44, asshown in the block formation of FIG. 6, in that the work head 46 of thesandwiching device 43 trails the wafer sheet lying on the transportdevice 44, until it catches up with the same. At the rear margin of thework head 46, similar to the transfer head 30 of the transfer device ofFIG. 6, a rear stop projects downwards over the uncoated underside ofthe preliminary block held by the work head 46. The work head is broughtclose from behind with its rear stop to the rear edge of the wafer sheetand then pushes the same on the transport device 44 in transportdirection until the work head 46 has positioned the preliminary block ontop of the wafer sheet.

The motion of the respective preliminary block held by the work head 46can be synchronized with the wafer sheet lying on the transport device44, as shown in the block formation illustrated in FIG. 7, in that thewafer sheet trails the work head 46 of the sandwiching device 43,similar to the transfer head 30 of the transfer device of FIG. 7, untilit catches up from behind with the preliminary block held by the workhead 46. At its frontal margin, the work head 46 has a frontal stopsimilar to the transfer head 30 of the transfer device of FIG. 7, whichprojects downwards over the uncoated underside of the preliminary blockheld by the work head 46. The wafer sheet trails after the work head 46,until the frontal edge of the wafer sheet hits against the frontal stop.Subsequently the wafer sheet is held back by the work head 46, until thework head 46 has positioned the preliminary block on top of the wafersheet.

FIG. 12 shows an installation for the production of triple-layer filledflat wafer blocks 53, whereby uncoated wafer sheets 54 and coated wafersheets 55 are fed on a multiple part transport device 44 a, 44 b, 44 cto a sandwiching machine, of which only the vertically up and downmovable work head 56 is represented. The work head 56 has a downwardspointing frontal side facing the transport device 44, on which a holdingdevice with an air cushion is provided. The air cushion is actuated withnegative pressure for seizing the uncoated upper side of a preliminaryblock, and with overpressure for the release of the finished waferblock. The work head 56 is moved vertically up and down by thesandwiching device into separate work positions, which are at differentdistances from the transport device 44. The sandwiching device designedas a vertically movable slide carriage or as a multiaxial handlingautomaton moves the work head 56 in a guided motion back and forthbetween its work positions.

FIG. 13 shows a further installation for the production of filled waferblocks. This installation comprises a lower transport device 57consisting of several transport devices 57 a, 57 b, 57 c, 57 d, 57 e, 57f, 57 g, arranged one after the other in transport direction, defining alower transport level. On the first transport device 57 a uncoated wafersheets are fed to the installation, which are joined in the installationto form triple-layer filled wafer block. The second transport device 57b is designed as a switch, which divides the uncoated wafer sheets inupper and lower wafer sheets.

The lower wafer sheets are transferred in the lower transport level tothe third transport device 57 c, which transfers these wafer sheets asan unbroken band to a fourth transport device 57 d, on which the wafersheets pass by a spread applicator 58 and are coated on their uppersides with spread.

The upper wafer sheets are transferred by the transport device 57 b toan upper transport device 59, which bridges the third transport device57 c and the spread applicator 58 in that it transports the uncoatedupper wafer sheets to a positioning station 60 arranged at the end ofthe fourth transport device 57 d, where the uncoated upper wafer sheetsare positioned on top of separate lower coated wafer sheets lying on thefourth transport device 57 d.

The fifth transport device 57 e is part of a calibration device 61,wherein the uncoated wafer sheets positioned on top of the coated wafersheets are joined together to form two-layer filled wafer blocks, whilethe coated wafer sheets pass the calibration station 60 unrestricted.

The two-layer preliminary blocks and the coated wafer sheets are fed onthe sixth transport device 57 f to a sandwiching device 62 with avertically up and down movable work head, which in its first workposition seizes a two-layer preliminary block supplied by the sixthtransport device 57 f at its uncoated upper side, holding it securelyand lifting it, and in its second work position positions the two-layerpreliminary block on top of a coated wafer sheet supplied by the sixthtransport device 57 f. This is joined with the superposed two-layerpreliminary block to form a triple-layer wafer block in a furtherseventh transport device 57 g provided with a calibrating device 63.

This embodiment of the sandwiching device 62 can be replaced by one ofthe embodiments of the sandwiching device 45 described in connectionwith FIGS. 10 and 11.

What is claimed is:
 1. A method of making filled wafer blocks in astacking station, said method comprising the steps of: 1) feedingpreliminary blocks at a lower level to said stacking station, 2) feedingwafer sheets coated on their upper side with spread as coated upperwafer sheets at an upper level to said stacking station, 3) grasping acoated upper wafer sheet on its underside, turning it upside down andlowering the reversed coated upper wafer sheet to a preliminary block,4) joining said lowered reversed coated upper wafer sheet with saidpreliminary block to form a filled wafer block, and 5) removing saidfilled wafer block at said lower level from said stacking station. 2.The method according to claim 1, wherein said coated upper wafer sheetis first turned upside down and lowered to said preliminary block in asingle guided movement.
 3. The method according to claim 1, wherein saidcoated upper wafer sheet is lowered to said preliminary block in asingle guided movement and turned upside down while being lowered. 4.The method according to claim 1, wherein a coated upper wafer sheet isturned upside down, lowered to a preliminary block and joined with it toform a filled wafer block as a new preliminary block for the next coatedupper wafer sheet to be reversed and lowered.
 5. The method according toclaim 4, wherein at least one further coated upper wafer sheet is turnedupside down, lowered to and joined with a previously formed newpreliminary block to form a filled wafer block being removed from saidstacking station at said lower level.
 6. The method according to claim1, wherein said lowered and reversed coated upper wafer sheet issynchronized with the motion of a moving preliminary block before it isjoined with said preliminary block to form a filled wafer block.
 7. Themethod according to claim 1, wherein each lowered reversed coated upperwafer sheet is stopped, before it is joined with a preliminary block toform a filled wafer block.
 8. The method according to claim 1, wherein alowered and reversed coated upper wafer sheet is first synchronized withthe motion of a moving preliminary block and then moved synchronouslywith said moving preliminary block while being joined with said movingpreliminary block to form a filled wafer block.
 9. The method accordingto claim 1, wherein a moving preliminary block is first synchronizedwith the motion of a lowered and reversed coated upper wafer sheet andthen moved synchronously with said lowered and reversed coated upperwafer sheet while being joined with said lowered and reversed coatedupper wafer sheet to form a filled wafer block.
 10. The method accordingto claim 1, wherein said lowered and reversed coated upper wafer sheetis pressed downwards against said preliminary block to form a filledwafer block.
 11. The method according to claim 1, wherein saidpreliminary block is pressed upwards against said lowered and reversedcoated upper wafer sheet to form a filled wafer block.
 12. The methodaccording to claim 1, wherein a grasped coated upper wafer sheet ismoved to a moving preliminary block in a single guided movement duringwhich said grasped coated upper wafer sheet is turned upside down,lowered to said moving preliminary block, trailing said movingpreliminary block, synchronized with said moving preliminary block andpressed downwards against said synchronously moving preliminary block toform a filled wafer block.
 13. The method according to claim 1, whereina grasped coated upper wafer sheet is moved to a moving preliminaryblock in a single guided movement during which said grasped coated upperwafer sheet is turned upside down, lowered to said moving preliminaryblock, trailing said moving preliminary block and synchronized with saidmoving preliminary block and wherein said moving preliminary block ispressed upwards against said synchronously moving, lowered and reversedcoated upper wafer sheet to form a filled wafer block.
 14. The methodaccording to claim 1, wherein each coated upper wafer sheet is centeredin said upper level before it is grasped on its underside and turnedupside down.
 15. The method according to claim 1, wherein for eachfilled wafer block to be made, the position of a preliminary block isregistered on said lower level by means of sensor monitoring before acoated upper wafer sheet is grasped on its underside and turned upsidedown.
 16. The method according to claim 1, wherein said preliminaryblocks are uncoated wafer sheets.
 17. The method according to claim 1,wherein said preliminary blocks are wafer sheets coated on their upperside with spread.
 18. A method of making filled wafer blocks in astacking station, said method comprising the steps of: 1) feedingpreliminary blocks coated on their upper side with spread at a lowerlevel to said stacking station, 2) feeding uncoated wafer sheets asupper wafer sheets at an upper level to said stacking station, 3)grasping an upper wafer sheet on its underside, turning it upside downand lowering the reversed coated upper wafer sheet to a preliminaryblock, 4) joining said lowered reversed upper wafer sheet with saidcoated preliminary block to form a filled wafer block, and 5) removingsaid filled wafer block at said lower level from said stacking station.19. The method according to claim 18, wherein said upper wafer sheet isfirst turned upside down and lowered to said coated preliminary block ina single guided movement.
 20. The method according to claim 18, whereinsaid upper wafer sheet is lowered to said coated preliminary block in asingle guided movement and turned upside down while being lowered. 21.The method according to claim 18, wherein a lowered and reversed upperwafer sheet is synchronized with the motion of a moving coatedpreliminary block before it is joined with said coated preliminary blockto form a filled wafer block.
 22. The method according to claim 18,wherein each lowered reversed upper wafer sheet is stopped, before it isjoined with a coated preliminary block to form a filled wafer block. 23.The method according to claim 18, wherein a lowered and reversed upperwafer sheet is first synchronized with the motion of a moving coatedpreliminary block while being joined with it to form a filled waferblock.
 24. The method according to claim 18, wherein a moving coatedpreliminary block is first synchronized with the motion of a lowered andreversed upper wafer sheet while being joined with it to form a filledwafer block.
 25. The method according to claim 18, wherein said loweredand reversed upper wafer sheet is pressed downwards against said coatedpreliminary block to form a filled wafer block.
 26. The method accordingto claim 18, wherein said coated preliminary block is pressed upwardsagainst said lowered and reversed upper wafer sheet to form a filledwafer block.
 27. The method according to claim 18, wherein a graspedupper wafer sheet is moved to a moving coated preliminary block in asingle guided movement during which said grasped upper wafer sheet isturned upside down, lowered to said moving coated preliminary block,synchronized with said moving coated preliminary block and presseddownwards against said synchronously moving coated preliminary block toform a filled wafer block.
 28. The method according to claim 18, whereina grasped upper wafer sheet is moved to a moving coated preliminaryblock in a single guided movement during which said grasped upper wafersheet is turned upside down, lowered to said moving coated preliminaryblock and synchronized with said moving preliminary block and whereinsaid moving preliminary block and wherein said moving coated preliminaryblock is pressed upwards against said synchronously moving lowered andreversed upper wafer sheet to form a filled wafer block.
 29. The methodaccording to claim 18, wherein each upper wafer sheet is centered insaid upper level before it is grasped on its underside and turned upsidedown.
 30. The method according to claim 18, wherein for each filledwafer block to be made the position of a coated preliminary block isregistered on said lower level by means of sensor monitoring before acoated upper wafer sheet is grasped on its underside and turned upsidedown.
 31. A method of making filled wafer blocks in a stacking station,said method comprising the steps of: 1) feeding alternatively apreliminary block and at least one wafer sheet being coated on its upperside with spread on a transport level to said stacking station, 2)grasping a preliminary block on its uncoated upperside, lifting it fromsaid transport level, lowering it above a coated wafer sheet lying onsaid transport level and pressing it downwards against said coated wafersheet to form a filled wafer block lying on said transport level, 3)releasing said filled wafer block, and 4) removing said filled waferblock from said stacking station on said transport level.
 32. The methodaccording to claim 31, wherein for each further wafer sheet layer of thewafer block to be made said grasped preliminary block is once morelifted from said transport level, lowered above a further coated wafersheet lying on said transport level and pressed downwards against saidfurther coated wafer sheet to form a filled wafer block lying on saidtransport level.
 33. The method according to claim 31, wherein saidgrasped preliminary block is synchronized with the motion of a movingcoated wafer sheet before it is joined with said moving coated wafersheet to form a filled wafer block.
 34. The method according to claim31, wherein said grasped preliminary block is stopped before it isjoined with a coated wafer sheet to form a filled wafer block.
 35. Themethod according to claim 31, wherein said grasped preliminary block ismoved to a moving coated wafer sheet in a single guided movement duringwhich said grasped preliminary block is lifted from said transportlevel, lowered above said moving coated wafer sheet lying on saidtransport level, trailing said moving coated wafer sheet, synchronizedwith said moving coated wafer sheet and pressed downwards against saidsynchronously moving coated wafer sheet to form a filled wafer block.36. The method according to claim 31, wherein a coated wafer sheet lyingon said transport level and trailing said grasped preliminary block isfirst synchronized with the motion of, and then moved synchronouslywith, said grasped preliminary block being pressed downwards againstsaid synchronously moving wafer sheet to form a filled wafer block. 37.The method according to claim 31, further comprising the steps: joiningwafer sheets and coated wafer sheets in pairs outside said stackingstation to form two-layer wafer blocks and feeding said two-layer waferblocks as said preliminary blocks on said transport level to saidstacking station.
 38. The method according to claim 31, wherein saidpreliminary blocks are uncoated wafer sheets.
 39. A method of makingfilled wafer blocks in a stacking station, said method comprising thesteps of: 1) feeding alternatively a preliminary block and at least onewafer sheet being coated on its upper side with spread on a transportlevel to said stacking station, 2) grasping a preliminary block on itsuncoated upperside, lifting it from said transport level and lowering itinto a work position above a coated wafer sheet, 3) joining said coatedwafer sheet with said grasped preliminary block to form a filled waferblock by lifting said coated wafer sheet from said transport level andpressing it upwards against the underside of said preliminary block heldin its work position, 4) releasing said filled wafer block onto saidtransport level, and 5) removing said filled wafer block from saidstacking station on said transport level.
 40. The method according toclaim 39, wherein for each further wafer sheet layer of the wafer blockto be made said grasped preliminary block is once more lifted andlowered into a work position above a further coated wafer sheet which islifted and pressed upwards against the underside of said preliminaryblock held in its working position and wherein said grasped preliminaryblock is released onto said transport level after the last coated wafersheet of the wafer block to be made was lifted and pressed upwardsagainst the underside of said preliminary block held in its workposition.
 41. The method according to claim 39, wherein said graspedpreliminary block is synchronized with the motion of a moving coatedwafer sheet before it is joined with said moving coated wafer sheet toform a filled wafer block.
 42. The method according to claim 39, whereinsaid grasped preliminary block is stopped before it is joined with acoated wafer sheet to form a filled wafer block.
 43. The methodaccording to claim 39, wherein said grasped preliminary block is movedto a moving coated wafer sheet in a single guided movement during whichsaid grasped preliminary block is lifted from said transport level,lowered into a work position above said moving coated wafer sheet lyingon said transport level, trailing said moving coated wafer sheet andsynchronized with said moving coated wafer sheet which is pressedupwards against the underside of said synchronously moving preliminaryblock held in its work position.
 44. The method according to claim 39,wherein a coated wafer sheet lying on said transport level and trailingsaid grasped preliminary block is first synchronized with the motion ofand then moved synchronously with said grasped preliminary block andthen being lifted and pressed upwards against the underside of saidsynchronously moving preliminary block held in its work position. 45.The method according to claim 39, further comprising the steps: joiningwafer sheets and coated wafer sheets in pairs outside said stackingstation to form two-layer wafer blocks and feeding said two-layer waferblocks as said preliminary blocks on said transport level to saidstacking station.
 46. The method according to claim 39, wherein saidpreliminary blocks are uncoated wafer sheets.
 47. An apparatus formaking filled wafer blocks in a stacking station comprising: 1) a lowertransport device for supplying preliminary blocks and removing filledwafer blocks at a lower level, 2) an upper transport device forsupplying wafer sheets as upper wafer sheets at an upper level, and 3) asandwiching means for receiving an upper wafer sheet at said upperlevel, grasping said upper wafer sheet on its underside, turning itupside down, lowering it to a preliminary block and joining said loweredreversed upper wafer sheet with said preliminary block to form a filledwafer block.
 48. The apparatus according to claim 47, wherein saidsandwiching means comprises a transfer head with a wafer sheet holdingdevice for grasping an upper wafer sheet on its underside, said transferhead being movable from an upper receiving position with said wafersheet holding device turned upwards and arranged ahead said uppertransport device to a lower discharge position with said wafer sheetholding device turned downwards and arranged above said lower transportdevice.
 49. The apparatus according to claim 48, wherein said wafersheet holding device comprises an air cushion for grasping a wafer sheeton its underside by negative pressure and releasing said grasped wafersheet by overpressure.
 50. The apparatus according to claim 48, whereinsaid transfer head comprises a frontal stop for the frontal margin of apreliminary block, said frontal stop is arranged at the frontal marginof said transfer head and projects over a wafer sheet held by the wafersheet holding device of said transfer head.
 51. The apparatus accordingto claim 48, wherein said transfer head comprises a rear stop for therear margin of a preliminary block, said rear stop is arranged at therear margin of said transfer head and projects over a wafer sheet heldby the wafer sheet holding device of said transfer head.
 52. Theapparatus according to claim 48, wherein said transfer head is swingablefrom its upper receiving position to its lower discharge position abouta horizontal axis arranged between said upper level and said lowerlevel.
 53. The apparatus according to claim 48, wherein said sandwichingmeans comprises a multiaxial handling automaton associated with saidlower transport device for moving and turning said transfer head whichis mounted at the free end of a rotatable arm of an outrigger rotatableabout a vertical axis and bendable about a horizontal axis and equippedwith said rotatable arm which is rotatable about an axis perpendicularto said bending axis.
 54. The apparatus according to claim 47, whereinsaid sandwiching means comprises a movable transfer head with a wafersheet holding device for grasping an upper wafer sheet on its undersideand said sandwiching means further comprises an elevating tableassociated with said lower transport device for lifting a preliminaryblock from said lower level, said transfer head being movable from anupper receiving position with said wafer sheet holding device turnedupwards and arranged ahead said upper transport device to a lowerdischarge position with said wafer sheet holding device turned downwardsand arranged above said elevating table, said elevating table lifting apreliminary block from said lower level to the lower discharge positionof said transfer head for joining said preliminary block with a reversedupper wafer sheet held by said transfer head.
 55. The apparatusaccording to claim 54, wherein said wafer sheet holding device comprisesan air cushion for grasping a wafer sheet on its underside by negativepressure and releasing said grasped wafer sheet by overpressure.
 56. Theapparatus according to claim 54, wherein said transfer head comprises afrontal stop for the frontal margin of a preliminary block, said frontalstop is arranged at the frontal margin of said transfer head andprojects over a wafer sheet held by the wafer sheet holding device ofsaid transfer head.
 57. The apparatus according to claim 54, whereinsaid transfer head comprises a rear stop for the rear margin of apreliminary block, said rear stop is arranged at the rear margin of saidtransfer head and projects over a wafer sheet held by the wafer sheetholding device of said transfer head.
 58. The apparatus according toclaim 54, wherein said transfer head is swingable from its upperreceiving position to its lower discharge position about a horizontalaxis arranged between said upper level and said lower level.
 59. Theapparatus according to claim 54, wherein said sandwiching meanscomprises a multiaxial handling automaton associated with said lowertransport device for moving and turning said transfer head which ismounted at the free end of a rotatable arm of an outrigger rotatableabout a vertical axis and bendable about a horizontal axis and equippedwith said rotatable arm which is rotatable about an axis perpendicularto said bending axis.
 60. The apparatus according to claim 54, whereinsaid elevating table comprises an upwards facing support surfaceparallel to said lower level and a stop perpendicular to said lowerlevel for the frontal margin of a preliminary block.
 61. An apparatusfor making filled wafer blocks in a stacking station comprising: 1) atransport device for alternatively supplying a preliminary block and atleast one coated wafer block on the same level, and 2) a sandwichingmeans for grasping a preliminary block on its uncoated upper side,lifting it from said transport device, lowering it above a coated wafersheet and joining it with said coated wafer sheet to form a filled waferblock.
 62. The apparatus according to claim 61, wherein said sandwichingmeans comprises a work head with a holding device for grasping apreliminary block on its uncoated upperside, said work head beingmovable into a lower position and lowerable at least one upper workposition for joining said grasped preliminary block with a coated wafersheet to form a filled wafer block.
 63. The apparatus according to claim62, wherein said holding device comprises an air cushion for grasping apreliminary block on its coated upperside by negative pressure andreleasing said grasped preliminary block by overpressure.
 64. Theapparatus according to claim 62, wherein said work head comprises afrontal stop for the frontal margin of a coated wafer sheet, saidfrontal stop is arranged at the frontal margin of said work head andprojects below a preliminary block held by the holding device of saidwork head.
 65. The apparatus according to claim 62, wherein said workhead comprises a rear stop for the rear margin of a coated wafer sheet,said rear stop is arranged at the rear margin of said work head andprojects below a preliminary block held by the holding device of saidwork head.
 66. The apparatus according to claim 62, wherein saidsandwiching means comprises a handling automaton associated with saidtransport device for moving said work head which is mounted at the freeend of an outrigger bendable about a horizontal axis.
 67. The apparatusaccording to claim 66, wherein said outrigger of said handling automatonis rotatable about a vertical axis.
 68. An apparatus according to claim61, further comprising a preceding sandwiching section for making filledtwo-layer wafer blocks supplied as preliminary blocks at said transportlevel to said stacking station, wherein along said transport device arearranged in succession: 1) an upper transport device for supplyinguncoated wafer sheets, 2) a station for positioning uncoated wafersheets on separate coated wafer sheets lying on said transport device,and 3) a calibrating device for joining uncoated and coated wafer sheetsto form a filled two-layer wafer blocks.
 69. The apparatus according toclaim 61, wherein said sandwiching means comprises a movable work headwith a holding device for grasping a preliminary block on its uncoatedupperside and said work head being movable into a lower position andsaid sandwiching means further comprises an elevating table associatedwith said transport device for lifting each preliminary block and eachcoated wafer sheet from said transport level, said work head beingmovable from a lower preliminary block grasping position to at least oneupper work position for joining the grasped preliminary block with acoated wafer sheet lifted by said elevating table.
 70. The apparatusaccording to claim 67, wherein said holding device comprises an aircushion for grasping a preliminary block on its uncoated upperside bynegative pressure and releasing said grasped preliminary block byoverpressure.
 71. The apparatus according to claim 69, wherein said workhead comprises a frontal stop for the frontal margin of a coated wafersheet, said frontal stop is arranged at the frontal margin of said workhead and projects below a preliminary block held by the holding deviceof said work head.
 72. The apparatus according to claim 69, wherein saidwork head comprises a rear stop for the rear margin of a coated wafersheet, said rear stop is arranged at the rear margin of said work headand projects below a preliminary block held by the holding device ofsaid work head.
 73. The apparatus according to claim 69, wherein saidsandwiching means comprises a handling automaton associated with saidtransport device for moving said work head which is mounted at the freeend of an outrigger bendable about a horizontal axis.
 74. The apparatusaccording to claim 73, wherein said outrigger of said handling automatonis rotatable about a vertical axis.
 75. The apparatus according to claim69, wherein said elevating table comprises an upwards facing supportface parallel to said lower level and a stop perpendicular to said lowerlevel for the frontal margin of said preliminary blocks and said coatedwater sheets.
 76. An apparatus according to claim 69, further comprisinga preceding sandwiching section for making filled two-layer wafer blockssupplied as preliminary blocks at said transport level to said stackingstation, wherein along said transport device are arranged insuccession: 1) an upper transport device for supplying uncoated wafersheets, 2) a station for positioning uncoated wafer sheets on separatecoated wafer sheets lying on said transport device, and 3) a calibratingdevice for joining uncoated and coated wafer sheets to form a filledtwo-layer wafer blocks.